His keynote last year at Macworld turned out to be his last, when he announced the new iPhone 3G.
The Apple faithful must ponder a future without Jobs.
"He is the leader; he is their icon and I think it's important for people because without him, this movement there will be some questions about where it goes in the future," Piper Jaffray senior research analyst Gene Munster said.
More than 40,000 people are expected to attend Macworld this week. They are taking Jobs' health problem in stride.
"I think there's some little problems, and he told people so they could trust him again, that's about it it's no really big deal," Macworld exhibitor Raphael Sebbe said.
The editor of tech blog Valleywag.com says it may be time for Jobs and Apple to part ways.
"Jobs has done wonderful things, he saved the company, it was on its knees, it was almost out of cash before he got there," Owen Thomas said. "He launched the iPod, he launched the iPhone, he's a genius at new products, but his health has become a distraction."
Tom Krazit covers Apple for Cnet.com. He says Apple has many other ways to market its technology, including Apple's retail stores.
"They have places where you can see, feel and touch Apple products all over the globe, so it is a very different era for Apple; I'm not sure, to answer your question, if they need that anymore," Krazit said.
That raises questions whether trade shows are dying.
Attendance is expected to drop 10 percent at this week's Consumer Electronics Show in Las Vegas. At Macworld, Apple may unveil an upgraded Mac Mini and some new iPhone applications, but nothing revolutionary is expected at either show.
